Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology最新文献

{"title":"Noise in Ultrashort Elastic Membrane Nanotube","authors":"K. A. Ivanova,&nbsp;P. V. Bashkirov","doi":"10.1134/S1990747822050063","DOIUrl":"10.1134/S1990747822050063","url":null,"abstract":"<p>Fluctuations of the ion current in elastic nanopores are studied in a wide frequency range and a complete description of their noise characteristics is presented. The lumen of ultrashort (&lt;200 nm) lipid nanotubes (usNT) filled with an electrolyte solution was used as a model of an elastic nanopore. It is shown that at low frequencies (<i>f</i> &lt; 300 Hz) the 1/<i>f</i> noise type prevails. This low frequency noise was analyzed at different salt concentrations and nanopore geometries and it was found that the 1/<i>f</i> noise power is proportional to the reciprocal of the number of charge carriers, which is in good agreement with the empirical Hooge relation. Linear approximation showed that the Hooge parameter for elastic nanopores is (2.5 ± 0.5) × 10^–3, which turned out to be an order of magnitude higher than for solid analogs. In the high-frequency regime (<i>f</i> &gt; 1 kHz), white noise becomes dominant, the power density of which depends linearly on the signal bandwidth and, as the length of the usNT decreases and the ionic strength increases, it is in good agreement with its representation as the sum of the Johnson–Nyquist thermal noise and the Schottky shot noise.</p>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"16 4","pages":"320 - 327"},"PeriodicalIF":0.5,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4380663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physico-Chemical Mechanisms of the Functioning of Membrane-Active Proteins of Enveloped Viruses","authors":"O. V. Batishchev","doi":"10.1134/S1990747822050038","DOIUrl":"10.1134/S1990747822050038","url":null,"abstract":"<p>Over the past few years, the attention of the whole world has been riveted to the emergence of new dangerous strains of viruses, among which a special place is occupied by coronaviruses that have overcome the interspecies barrier in the past 20 years: SARS viruses (SARS), Middle East respiratory syndrome (MERS), as well as a new coronavirus infection (SARS-CoV-2), which caused the largest pandemic since the Spanish flu in 1918. Coronaviruses are members of a class of enveloped viruses that have a lipoprotein envelope. This class also includes such serious pathogens as human immunodeficiency virus (HIV), hepatitis, Ebola virus, influenza, etc. Despite significant differences in the clinical picture of the course of disease caused by enveloped viruses, they themselves have a number of characteristic features, which determine their commonality. Regardless of the way of penetration into the cell—by endocytosis or direct fusion with the cell membrane—enveloped viruses are characterized by the following stages of interaction with the target cell: binding to receptors on the cell surface, interaction of the surface glycoproteins of the virus with the membrane structures of the infected cell, fusion of the lipid envelope of the virion with plasma or endosomal membrane, destruction of the protein capsid and its dissociation from the viral nucleoprotein. Subsequently, within the infected cell, the newly synthesized viral proteins must self-assemble on various membrane structures to form a progeny virion. Thus, both the initial stages of viral infection and the assembly and release of new viral particles are associated with the activity of viral proteins in relation to the cell membrane and its organelles. This review is devoted to the analysis of physicochemical mechanisms of functioning of the main structural proteins of a number of enveloped viruses in order to identify possible strategies for the membrane activity of such proteins at various stages of viral infection of the cell.</p>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"16 4","pages":"247 - 260"},"PeriodicalIF":0.5,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S1990747822050038.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4378443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"pH Changes in the Mitochondrial Matrix and Cytosol under Glutamate Deregulation of Ca2+ Homeostasis in Cultured Rat Hippocampal Neurons","authors":"A. M. Surin,&nbsp;L. R. Gorbacheva,&nbsp;I. G. Savinkova,&nbsp;R. R. Sharipov,&nbsp;V. G. Pinelis","doi":"10.1134/S1990747822040079","DOIUrl":"10.1134/S1990747822040079","url":null,"abstract":"<p>The effect of high concentrations of glutamate (Glu) on primary cultures of neurons from the rat brain led to a strong depolarization of mitochondria, which developed synchronously with a secondary increase in the intracellular free Ca²⁺ concentration (delayed calcium deregulation, DCD). Simultaneously with measurements of the intracellular free Ca²⁺ concentration ([Ca²⁺]_i), pH was measured in the mitochondrial matrix (pH_m) and cytosol (pH_c) of neurons when exposed to a toxic dose of Glu (100 µM). For this purpose, pH-sensitive green fluorescent protein mtYFP in mitochondria and pH-sensitive red fluorescent protein mKate in cytosol were expressed in primary cultures from the hippocampus of newborn rats. The resulting neuronal culture was loaded with the Ca²⁺ indicator Fura-FF; [Ca²⁺]_i, pH_m and pH_c were simultaneously measured in those neurons that expressed both mtYFP and mKate. It was found that during the first phase of the [Ca²⁺]_i response to Glu, when partial depolarization of mitochondria was observed, there was an increase in the pH gradient between the mitochondrial matrix and the cytosol (ΔpH), which compensated for the decrease in the electrical component of the mitochondrial potential (∆Ψ_m), thereby maintaining the constancy of the electrochemical potential of mitochondria. The development of DCD led to an abrupt decrease in ∆Ψ_m and ΔpH in the soma of neurons; however, a complete collapse of ΔpH was not observed. This may mean that DCD was not caused by a nonspecific megapore in the inner mitochondrial membrane (mPTP), as is commonly believed. Alternatively, part of the mitochondria in the soma of neurons could retain the barrier properties of the inner membrane and did not form mPTP even with the development of DCD and reaching a high [Ca²⁺]_i plateau.</p>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"16 3","pages":"236 - 245"},"PeriodicalIF":0.5,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4595685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physiology of Ranvier Nodes in Living Myelinated Nerve Fibers","authors":"O. S. Sotnikov,&nbsp;S. V. Revenko","doi":"10.1134/S1990747822040067","DOIUrl":"10.1134/S1990747822040067","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>A fixed histological preparation cannot reveal the dynamics of morphophysiological objects being merely a basis for hypothetic physiology. At the same time, intravital microscopy of mobile and changing structures can be considered as a branch of cell physiology. The present study focused on revealing the features of this chapter of neurophysiology in relation to nerve fibers. Importantly, the preparation of living neurons isolated by the method of Tasaki inevitably produces mechanical lesions in Ranvier node structure of unknown scale and importance. These lesions can be manifested by deformation or entire elimination of the cone-shaped myelinated regions of the node and/or fiber bulb, as well as by the changes of the nodal gap. Similar alterations can emerge in the intact fiber during a long-term survival in Ringer’s solution. Electron microscopy showed that in hypotonic solutions, swelling and increase in the volume of neuroplasm in the paranodal loops were accompanied by its expansion into the axoplasmic territory in the cone during narrowing of the axon. These processes were reversible, and they probably reflected a novel form of metabolic transmembrane neuron–glial exchange of glucose, amino acids, and other low-molecular weight compounds leading to the formation of integrated cytoplasm of the nerve fiber. The loss of clear boundary of the myelinated cones of the node and/or fiber bulb depended on a large-scale exfoliation of individual main dense lines of Robertson and on flooding the series of paranodal loops. Hypertonic (2 M) solution of urea, which cannot provoke swelling of the cytoplasm but can denature the proteins, also induced similar alterations in the node of Ranvier. Consequently, the described changes in the nodes were not associated with the phenomenon of external osmotic changes, but with the influence of nonspecific physical alterations in conformation of axoplasmic proteins. The voltage clamp experiments with recording of nodal ionic currents demonstrated the correspondence of structural alterations to electrophysiological changes in sodium, potassium, and leakage conductance. The experiments with sodium channel modifier batrachotoxin revealed no structural alterations in Ranvier nodes during 1 h. The present and reviewed data indicate that the nodal changes probably result not from the structural alterations of axolemmal proteins, but from the conformational rearrangements of the axoplasmic ones.</p></div></div>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"16 3","pages":"224 - 235"},"PeriodicalIF":0.5,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4890432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Long-liver and a Knight of Science. To the 100th Anniversary of B. I. Khodorov","authors":"P. D. Bregestovski","doi":"10.1134/S1990747822040080","DOIUrl":"10.1134/S1990747822040080","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>An outstanding neurophysiologist Boris Israelievich Khodorov made an enormous contribution to the study of excitable biological membranes, to the biophysics and physiology of the nervous system. Several generations of biophysicists, physiologists, and neurobiologists learned from his monographs and textbooks. Together with his students and colleagues, he created high-quality electrophysiological facilities for recording of electrical signals in the Ranvier node of isolated nerve fibers and also developed other original experimental models for studying the excitability of ion channels. Using these models, the mechanisms of action of various anesthetics and other substances on the generation of action potentials were investigated. The parameters of activation and inactivation of sodium currents were analyzed using mathematical models, primarily the Hodgkin–Huxley equations. The results of these studies have been included in textbooks, books and manuals on biophysics and physiology of the nervous system. The assumptions made in the early works of B.I. Khodorov that local anesthetics and antiarrhythmic drugs pass to the pore of the ion channel through the hydrophobic pathway of the lipid membrane received convincing confirmation and evidence half a century later, after obtaining the crystal structure of the sodium channel in 2011. Pioneering studies of B.I. Khodorov on the dysregulation of calcium homeostasis of brain neurons during glutamate receptor hyperstimulation, as well as elucidating the role of mitochondria in brain cell neurotoxicity, received wide international recognition. The article provides details of the life and scientific achievements of this outstanding scientist.</p></div></div>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"16 3","pages":"183 - 189"},"PeriodicalIF":0.5,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4890437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disruption of Calcium Homeostasis and Following Changes in Calcium Signaling in Neurons and Glial Cells in Response to Photodynamic Treatment","authors":"B. A. Dzreyan,&nbsp;A. M. Khaitin,&nbsp;S. V. Demyanenko","doi":"10.1134/S1990747822040031","DOIUrl":"10.1134/S1990747822040031","url":null,"abstract":"<p>Photodynamic impact on neurons and glial cells, causing oxidative stress and ischemic damage, is accompanied by disruption of calcium homeostasis and activation or suppression of diverse calcium-dependent mechanisms, such as calcium pumps and channels, calcium-dependent signaling or executive proteins, and other signaling systems that interact with calcium pathway, like ion channels, pumps and exchangers, nitric oxide, glutamate, and others. The cascade of processes initiated by oxidative stress and ischemia in nervous tissue, includes both protective responses and apoptotic or necrotic cell death scenarios. This mini review surveys the publications on these processes and compares them with the data obtained in our laboratory on the model of photothrombotic stroke on rat brain in vivo and the model of photodynamic treatment on crayfish mechanoreceptor in vitro. These areas of research are driven by the need to find methods of emergency neuroprotection in ischemic stroke and to improve the accuracy and efficiency of photodynamic therapy of tumors with minimized damage to benign tissues. A proteomic study of the penumbra region in the photothrombotic stroke model revealed changes in the expression of a number of calcium-dependent proteins associated with impaired calcium homeostasis and having either a protective or damaging tendency. Inhibitory analysis of the effects of photo-oxidative stress on the crayfish stretch receptor model revealed the involvement of a number of proteins in the calcium-dependent pathway in neuronal or glial cell death or survival. In this paper, these data are analyzed and summarized to identify promising directions for further research.</p>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"16 3","pages":"217 - 223"},"PeriodicalIF":0.5,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4890431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Insights into Function of Ionotropic Glutamate Receptors","authors":"M. V. Yelshanskaya,&nbsp;A. I. Sobolevsky","doi":"10.1134/S1990747822040043","DOIUrl":"10.1134/S1990747822040043","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>Ionotropic glutamate receptors (iGluRs) mediate fast excitatory neurotransmission. They are implicated in nervous system development and function, while their dysfunction is associated with neurological and psychiatric disorders. In this review, we describe recent progress in structural studies of iGluRs and how crystal and cryo-EM structures helped determining the principles of iGluR architecture and assembly, and the mechanisms of activation, desensitization and regulation by auxiliary subunits, positive and negative allosteric modulators, and ion channel blockers. The new structural insights facilitate better understanding of iGluR physiological and pathophysiological roles in functioning of the central nervous system and provide valuable information for structure-based drug design.</p></div></div>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"16 3","pages":"190 - 206"},"PeriodicalIF":0.5,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4890451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Na+,K+-ATPase As a Polyfunctional Protein","authors":"O. D. Lopina,&nbsp;O. V. Bukach,&nbsp;S. V. Sidorenko,&nbsp;E. A. Klimanova","doi":"10.1134/S1990747822040055","DOIUrl":"10.1134/S1990747822040055","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>Since the discovery of Na⁺,K⁺-ATPase by Jens Skou in 1957, this enzyme has been considered exclusively as a transporter that ensures the active transport of Na⁺ and K⁺ ions across the cell plasma membrane; therefore, its structure and mechanism of functioning, as well as its involvement in secondary ion transport systems have been studied in detail. In the present review, the data on the structure and functioning of the enzyme are briefly reviewed. The role of Na⁺,K⁺-ATPase as a receptor for cardiotonic steroids (CTS), whose binding to the enzyme initiates a variety of signaling pathways through protein–protein interactions modified also by changes in the intracellular concentration of Na⁺ and K⁺ ions by inhibiting the Na⁺,K⁺-ATPase transport function and Ca²⁺, by mediating changes in Na/Ca-exchange activity, was described in more detail. All these provide a variety of CTS effects, including their effect on gene expression, the state of tight junctions, cell adhesion, induction of myocardial hypertrophy, stimulation of free-radical oxygen species generation, and initiation of cell death or survival depending on tissue type. Data on the discovery of endogenous CTS are presented, as well as an analysis of published data indicating that concentrations of endogenous CTS are so low that they are unlikely to cause inhibition of Na⁺,K⁺-ATPase. In this connection, the data on the enzyme activation by low doses of CTS are presented, and the idea of a possible summation of the concentrations of various steroids is suggested. Possible directions for the study of multiple functions of Na⁺,K⁺-ATPase are discussed in the conclusion.</p></div></div>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"16 3","pages":"207 - 216"},"PeriodicalIF":0.5,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4599405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Principles and Problems of Exosome Isolation from Biological Fluids","authors":"E. I. Yakubovich,&nbsp;A. G. Polischouk,&nbsp;V. I. Evtushenko","doi":"10.1134/S1990747822030096","DOIUrl":"10.1134/S1990747822030096","url":null,"abstract":"<p>Exosomes, the subclass of small membrane extracellular vesicles, have great diagnostic and therapeutic potential, but the lack of standardized methods for their efficient isolation and analysis limits the introduction of exosomal technologies into clinical practice. This review discusses the problems associated with the isolation of exosomes from biological fluids, as well as the principles of traditional and alternative methods of isolation. The aim of the presented review is to illustrate the variety of approaches based on the physical and biochemical properties of exosomes that can be used for exosome isolation. The advantages and disadvantages of different methods are discussed.</p>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"16 2","pages":"115 - 126"},"PeriodicalIF":0.5,"publicationDate":"2022-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S1990747822030096.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4654168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Dependence of the Channel-Forming Ability of Lantibiotics on the Lipid Composition of the Membranes","authors":"S. S. Efimova,&nbsp;E. V. Shekunov,&nbsp;D. N. Chernyshova,&nbsp;A. A. Zakharova,&nbsp;O. S. Ostroumova","doi":"10.1134/S1990747822020039","DOIUrl":"10.1134/S1990747822020039","url":null,"abstract":"<p>The role of various membrane components, phospholipids and lipopolysaccharides, in the formation and functioning of ion channels formed by lantibiotics of class A, nisin, and class B, cinnamycin and duramycin, was studied. Threshold concentrations of the tested lantibiotics were determined that cause ion channel formation and destruction of planar lipid bilayers. It was found that nisin was able to form ion channels with a conductance in the range from 2 to 600 pS at a concentration of more than 40 μM both in negatively charged lipid bilayers containing a specific adjuvant of gram-negative bacterial membranes, Kdo₂–lipid A, and in cardiolipin-containing membranes. The obtained results allowed suggesting that in model lipid membranes without lipid II, a precursor of peptidoglycan of gram-positive bacteria, which is a specific receptor of nisin, its role can be performed by Kdo₂–lipid A and cardiolipin. It was found that cinnamycin and its close analogue duramycin at concentrations of 1.5–3 μM induced step-like current fluctuations corresponding to the functioning of single ion channels with amplitudes from 5 to 30 pS and from 50 to 900 pS in membranes of phosphatidylethanolamine and cardiolipin-enriched bilayers, respectively. Based on the results obtained, we conclude that the channel-forming ability of cinnamycin and duramycin depends on the presence in the membrane of lipids prone to the formation of inverted hexagonal phases and the induction of spontaneous negative curvature in lipid monolayers.</p>","PeriodicalId":484,"journal":{"name":"Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology","volume":"16 2","pages":"144 - 150"},"PeriodicalIF":0.5,"publicationDate":"2022-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4651753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}